Carbohydrate Guide
The ketogenic diet explained: macros, benefits, and risks
Keto isn't just "low carb" — it's a specific macro ratio designed to push your body into a distinct metabolic state.
The macro split
A standard ketogenic diet typically targets roughly 70–80% of calories from fat, 15–25% from protein, and only about 5–10% from carbohydrate — often under 50g of carbs per day. That's dramatically below the standard 45–65% AMDR for carbs.[1] At that level, glycogen stores empty out and the body shifts to producing ketones from fat as its primary fuel source — the metabolic state called ketosis.
What to know before trying it
- The adaptation period can include fatigue, headaches, and irritability ("keto flu") as the body shifts fuel sources — see our full breakdown of low-carb diet effects
- High-intensity performance can suffer, since glycogen is the preferred fuel for fast, powerful efforts
- Not automatically appropriate for everyone — anyone on blood-sugar-lowering or blood-pressure medication should talk to a doctor before attempting it, since the diet can significantly affect both
Keep reading: What happens on a low-carb diet · What is glycogen? · How many carbs per day